Field of the Invention
The invention relates to a smart card including a microcircuit (or integrated circuit) provided with external contacts and one or more other components, including an accessible component, such as a display, a detector (for example a fingerprint detector) or a sender (for example an optical sender), i.e. a component that has to be accessible on the surface of the card (without necessarily projecting therefrom).
Description of Related Art
A standard method of fabricating a smart card incorporating a single microprocessor microcircuit consists in forming a cavity in the card support (which in practice is made of a plastic material) and sticking therein a module consisting of the microprocessor microcircuit and its external contacts connected to the microcircuit. On the subject see U.S. Pat. No. 6,372,541.
When the smart card is intended to incorporate, in addition to a microcircuit module (forming together with an antenna a system known as a communication interface), another electronic component that is accessible on the surface, the document WO 99/50790 proposes to connect the electronic component to the communication interface by means of conductive wires, temporarily fixing the resulting assembly against a first plastic material plate, placing a second plastic material plate on top of that assembly, an opening being provided either in the first plate or in the second plate to serve as a housing for the electronic component, and then fastening the two plates together, enclosing the interface and the electronic component.
The above method necessitates dedicated equipment for positioning the assembly in the middle of the plastic structure before the final manufacturing step and providing appropriate openings in the plates. Furthermore, the communication interface and the component accessible at the surface must be able to withstand the temperature at which the plates are fastened together, typically temperatures of at least 140° C., for example, in the case of laminating the plates as proposed in the document cited above.
The document EP-0 908 844 and U.S. Pat. No. 6,320,753, relating to an earlier invention of the Applicant, propose a smart card combining external contact areas and an antenna and comprising a microcircuit connected to the antenna and to external contact areas via connecting terminals, the antenna being disposed between a support and a plate and the connecting terminals being disposed facing corresponding connecting ends of the microcircuit. The microcircuit and the antenna are mounted separately and the concept of disposition between a plate and a support applies.
A sandwich configuration of the above kind is disclosed in the document EP-0 234 954, which describes a smart card formed of a PC card between two plates, and in U.S. Pat. No. 5,412,192, which relates to a card in whose support an antenna is buried and in which a display component is laminated to the interior of the card.
As indicated a propose the first prior art document, the diverse solutions are complex and using them often implies processing that it must be possible to carry out without damaging the components.
One aspect of the invention is a smart card including a microcircuit and one or more other components, including an accessible component, the fabrication of which is simple and reliable, without necessitating processes that are aggressive to the components or lead to mechanical weakening of the card, and in which bending forces applied to the card are advantageously localized at locations where they have only limited consequences.
Another aspect of the invention is a method of fabricating a smart card of the above kind.